1. Field of the Invention
The present invention relates to an apparatus for driving a gate storage type liquid crystal display (LCD) panel.
2. Description of the Related Art
Active matrix LCD panels using thin film transistors (TFT's) have been developed in terms of resolution and performance.
In a prior gate storage type active matrix LCD panel (see: T. P. Brody: "A 6.times.6 inch 20 lines-per-Inch Liquid-Crystal Display Panel", IEEE Trans. of Electron Devices, Vol. ED-20, No. 11, pp. 995-1001, Nov. 1973), each pixel has a storage capacitor formed on an adjacent gate line, to thereby increase the capacity of the pixels. As a result, the feed-through of gate pulse signals is reduced, and a pixel voltage deviation caused by the leakage current of liquid crystal cells and TFT's is reduced. This will be explained later in detail.
On the other hand, a two gate line driving method is applied to a storage capacitor line type active matrix LCD panel (see: Shinji Morozumi et al., "4.25-in and 1.51-in B/W and Full-Color LC Video Displays Addressed by Poly-Si TFT's", SID 84 Digest, pp. 316-319, 1984; Masahiro Adachi et al., "A High-Resolution TFT-LCD for a High-Definition Projection TV", SID 90 Digest, pp. 338-341, 1990). According to the two gate line driving method, in non-interlace scanning, the pulse width of a gate pulse signal applied to gate lines can be twice that of the conventional one gate driving method, to enlarge the margin of a write operation and reduce the frequency of operation. Also, when the ability of the TFT's is small or when the number of gate lines is large, effective use is made of the two gate line driving method. Further, since non-interlace scanning is used, the resolution is high and the flicker is small. This will be explained later in detail.
In the prior art, however, it is impossible to apply the two gate line driving method to a gate storage type active matrix LCD panel. This will also be explained later in detail.